I fly the 109g2 most of the time, but the style between the two is pretty much the same. Use the 109's climb rate to stay slightly above the target until your enemy gives you an opening for a shot. By "slightly above," I mean just high enough that he can't go nose up and zoom you for a shot without getting himself roped. While you're up there, it's best to be spiral climbing to keep him in your view and forcing him to burn E by turning with you (he'll burn a lot of E if he tries to pull hard on the turn for a lead shot).
When you see your opportunity, use rudder and ailerons to roll over quickly and make your pass and then get above him again. If you think you can hang with him, chop your throttle and saddle up. I generally carry gondolas, which means I don't saddle up often since most of the MA's planes will turn better than I do. If I blow the shot I get above him and set up again. If you don't carry gondies, saddling up is more of an option as I can turn with pretty much anything that's not a dedicated turner (spit5, japanese planes, hurris).
109's have lots of rudder authority, so don't be afraid to use rudder to set up shots, burn E, or roll.